Raising concerns over the depleting air quality in Uttar Pradesh, artificial lungs installed near Nagar Nigam office in Lalbagh area turned black within 24 hours. "This shows the air quality here. It took six days for the lungs to turn black in Delhi, 18 days in Bengaluru," said Ekta Shekhar, Director, Climate Agenda. She added, "In Lucknow, the lungs turned black by the very next day of the installation, within 24 hours." "We had used HEPA filters. There are loopholes in the National Clean Air Programme of the government. Till the time they are not addressed, the situation won`t be better in the state," Shekhar said. Besides UP, the overall air quality index (AQI) again deteriorated to `very poor` category on Sunday in the national capital after the level of harmful pollutants shot up. According to Centre-run SAFAR, Delhi`s AQI was docking at 382 in the morning.